SolarCoin (SLR) is a decentralised and open-source cryptocurrency forked from Litecoin in early 2014. It is backed by two forms of proof of work; one is the traditional cryptographic proof of work associated with a digital currency, while the other is Solar Renewable Energy Certificate (SREC) that has been generated and independently verified by a third party. SolarCoin is equitably distributed using both of these proofs of work as a means to reward renewable energy production. The intent is to provide an incentive to produce more solar electricity by rewarding the generators of solar electricity. In September 2015 the coin has become a pure proof-of-stake cryptocurrency paying an annual interest rate of 2%. Original announcement.

DistroWatch.com - BitKey

BitKey is a FREE, Debian-based live Linux distribution designed for Bitcoin users; it comes with specialist utilities to perform highly secure air-gapped Bitcoin transactions. It contains a swiss army knife of handy Bitcoin tools that support a wide range of usage models, including a few very secure ones which would otherwise be difficult to perform. The system boots into one of the three available modes: "cold-offline" - for creating a wallet and signing transactions; "cold-online" - for watching the wallet and preparing transactions; "hot-online" - standard usage but less secure as the private keys are known to the computer which is connected to the internet.

Pooled mining is a method of generating bitcoins (and other cryptocoins) where multiple users work together by pooling their computing resources, then split the block reward according to the contributed processing power. Mining in pools began when the difficulty for bitcoin mining increased to the point where it could take years for an individual miner to generate a block. The solution was for miners to pool their resources, usually through websites designed specifically for this purpose, so they could generate blocks faster.

Groestlcoin (GRS) is a decentralised, open-source cryptocurrency forked from Bitcoin in March 2014. The project's focus is to enable anybody with a standard computer to mine coins, using either the computer's central processing unit (CPU) or its graphcs processing unit (GPU). Groestlcoin is a hybrid proof-of-work/proof-of-stake coin which uses the ASIC-resistent Grøstl hashing algorithm to complete proof-of-work blocks. Starting at block 150,000, coins can also be generated by "staking" at a 2% annual interest. The total number of coins was set to 105 million, with the initial block reward at 25 GRS; this is reduced by 6% every 10,080 blocks. The block time is 60 seconds, while the difficulty is recalculated after each completed block of transactions. Original announcement.

Groestlcoin developer "gruve_p" has announced the release of Groestlcoin (GRS) 2.13.3, a major new release of the project's hybrid proof-of-work/proof-of-stake cryptocurrency which uses the ASIC-resistant Grøstl hashing algorithm for mining while also awarding a 2% annual interest on staked coins. This version is based on the recently-released Bitcoin Core 0.13 code: "v2.13.3 is now the official release version of Groestlcoin Core. On top of the new features and performance improvements, this update contains very important security fixes. It is recommended to upgrade to this version as soon as possible. What's new in version v2.13.3? This is a major release of Groestlcoin Core with many protocol level improvements and code optimizations, featuring the technical equivalent of Bitcoin v0.13.3 but with Groestlcoin-specific patches. On a general level, most of what is new is the ability to roll out several soft forks at once and the greatly anticipated segregated witness (segwit) innovation." See the detailed release announcement for a full changelog and upgrade instructions. Binary packages of Groestlcoin 2.13.3 are available for macOS and Windows; download links: Groestlcoin-Qt.dmg (20.8MB), groestlcoin_x64.msi (14.5MB), groestlcoin_x86.msi (11.8MB). Linux/UNIX users are welcome to compile their binary package from source code: v2.13.3.tar.gz (5.91MB, build instructions here).